CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income	$ 2,792	$ 3,485
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,943	3,509
Deferred income taxes	(135)	(1,394)
Stock-based compensation	235	407
Net change in unrealized gains and losses on investments	109	721
Net change in accrued interest, premiums, and discounts on investments	(5)	(77)
Adjustments to reconcile net income loss to cash provided by used in operating activities	6,939	6,651
Changes in operating assets and liabilities:
Accounts receivable	(2,087)	4,527
Inventories	7,307	(9,300)
Prepaid expenses	345	979
Other non-current assets	192	382
Accounts payable and accrued liabilities	(1,504)	167
Accrued income and other taxes	1,034	984
Other non-current liabilities	(728)	(62)
Cash flows from operating activities	11,498	4,328
Cash flows from investing activities:
Property, plant and equipment additions	(3,175)	(7,543)
Purchase of investments	(3,608)	(4,160)
Proceeds from sale of investments	228	52
Proceeds from maturities of investments	2,519	11,574
Cash flows from investing activities	(4,036)	(77)
Cash flows from financing activities:
Purchase of treasury stock	0	(613)
Shares tendered for employees' withholding taxes on stock-based compensation	(20)	(22)
Dividends paid	(3,872)	(3,784)
Cash flows from financing activities	(3,892)	(4,419)
Net change in cash and cash equivalents	3,570	(168)
Cash and cash equivalents at beginning of period	3,565	4,731
Cash and cash equivalents at end of period	7,135	4,563
Cash paid for:
Income taxes	$ 11	$ 146